Over the first 20 years, China was successful in reducing its population by about 300 million people. However, as the one-child policy was not enforced in the rural areas, it is not surprising that the “short-term plan” was not more triumphant.
A very negative result of this policy was the focus on trying to conceive males, raising the ratio of boys to girls to be disproportionately large. While incentives were offered to those who followed the rule, those who had second or third children were subjected to financial and very severe social difficulties.
The delay in marriage license policy was helpful because couples had to wait longer until they could have children. There are much greater benefits to having children within wedlock in China, so it makes sense that this part of the policy is has been somewhat successful. However, in rural areas especially, there is more pressure to have more children so they can contribute to the family income, and couples will go to great lengths to try to have more, including undocumented births, bribing doctors to claim they had twins, or actually paying the heavy fines for having them).
It is unlikely that the US will adopt a similar strategy, although it seems feasible that there might be a law increasing the age in which couples may obtain marriage licenses. This type of policy would be more readily accepted, I believe.
In the future, as China becomes more recognized as a world economic leader, it will have greater pressures to prove its efforts to reduce human rights violations As a result of this policy, there have been stories of kidnappings and infanticide, two unacceptable outcomes that must immediately be addressed.